1. Field of the Invention
The present invention is directed to specimen storage slides, and in particular, to methods of use and specimen storage slides for the transportation and storage of dried specimens.
2. Description of Related Art
In 1963 Guthrie developed a method for collecting blood samples on absorbent filtration media. The blood samples were dried and transported to the laboratory for analysis. Today, dried blood spots (DBS) are used for mandatory newborn screening programs in the U.S. and in many other nations worldwide. DBS methods have also become common in other medical and forensic applications.
With the advancement of analyte detection methods, primarily liquid chromatography combined with mass spectroscopy (LC-MS or LC-MS/MS), interest has been expanded for the use of DBS for preclinical and clinical applications in lieu of plasma. The small blood volumes required, and the lower transportation and storage costs, are the driving factors. For preclinical applications, there is a significant reduction in the number of-animals that are sacrificed, contributing to the ethics of DBS. Dried blood spots are also stable for an extended period of time, often measured in years if the DBS is kept dry. This eliminates the cold storage and shipping requirement needs of plasma, which will drastically reduce costs.
A change from plasma to DBS creates many new challenges to meet the requirements of public health. For the last two years, extensive method development for DBS has occurred in the Bioanalytical market to meet the requirements that are being defined by the U.S. Food and Drug Administration (hereinafter “FDA”) for meeting public health safety standards. The FDA, as the guardian of public health, will accept DBS studies only after they have met or exceeded predefined health standards that have been established for plasma.
A variety of fields implement the use of cards to store dried specimens. These specimens may include chemical samples, biological samples, and the like. For instance, dried blood spots stored on paper cards have been in use for years in a variety of fields ranging from clinical, preclinical, research, forensics, and the like. More recently there has been an increase in the use of dried blood spots in clinical applications, such as, in neo-natal screening, DNA analysis, disease analyses (infectious disease, blood glucose concentration, etc.), drug screenings, and the like. Preclinical applications for dried blood spots, such as, medical research, drug discoveries, and the like, are also becoming more prevalent.
In the collection of dried blood spots, a number of drops of obtained blood are deposited in predetermined locations on filter paper of a paper collection card. These collection cards include an absorbent filter paper that is encased within a cardboard frame, attached inside a cardboard card, or attached to a paper sheet. The collection cards may also be provided with a source for sample identification, such as, a demographic portion where information about the sample and the submitter's identification can be entered. The blood specimen is allowed to dry on the collection card for storage, transportation and/or later use thereof.
However, a detriment of the currently available specimen collection cards is that since they are composed of either paper sheets or cardboard these conventional collection cards are flimsy and easily damaged. Also, in collection cards having a paper or cardboard frame encasing the filter paper media, the frame is typically not much thicker than the filter paper media it encases. As such, when one or more of these types of cards are stacked upon one another, their respective filter paper medias contact each other causing sample cross contamination, which is highly undesirable. Accordingly, it is often necessary to store each framed paper or cardboard collection card in an envelope separate from one another.
Furthermore, both current and future clinical and preclinical application systems or equipment are leaning towards automated handling, automated processing, and/or automated sample collection. Currently available paper and/or cardboard collection cards are inadequate for automated handling, processing, and/or sample collection due to their flimsiness or lack of dimensional stability. Rather, these conventional cards must be individually hand picked and placed into or onto the automated systems and equipment to prevent damage thereto, which in turn, leads to slower processing times and more costly analyses.
Accordingly, a need exists in the art for improved specimen collection storage devices that are durable, easily useable, are structurally and mechanically stable, have sufficiently rigidity for handling and processing, avoid specimen cross contamination, are adapted for automated handling, automated processing, and/or automated sample collection, and allow for faster processing times and reduced costs.